> ## Documentation Index
> Fetch the complete documentation index at: https://docs.waterfall.io/llms.txt
> Use this file to discover all available pages before exploring further.

# One GTM API for contacts and companies

> Find prospects, enrich contact and company profiles, find emails and mobile numbers, verify emails, and check job changes with the Waterfall API.

Waterfall brings together 30+ data vendors through one B2B data API. Find people at target accounts, match emails to business profiles, find contact details, and check whether existing contacts have changed jobs.

Use it to build signup enrichment, prospecting, and CRM workflows with the data your team needs. [About Waterfall](https://docs.waterfall.io/v1/about-waterfall.md) explains how it fits into your stack.

> **[Explore use cases](https://docs.waterfall.io/v1/use-cases/overview.md)**
>
> Start with a signup, target account, or CRM record and see the workflow.

> **[Use with agents](https://docs.waterfall.io/v1/skills-overview.md)**
>
> Run a lookup with an agent or build Waterfall into your application.

> **[Evaluate Waterfall](https://docs.waterfall.io/v1/evaluate-waterfall.md)**
>
> Compare useful results, match quality, and cost on your own records.

> **[Make your first request](https://docs.waterfall.io/v1/quickstart.md)**
>
> Launch a contact enrichment job and retrieve its result.

Already know what you want to build? [Choose an API](https://docs.waterfall.io/v1/introduction.md) to compare the inputs, results, and availability of each capability.

## What do you want to build?

| Your task | Start here |
| - | - |
| See who is behind a signup email | [Signup enrichment](https://docs.waterfall.io/v1/use-cases/signup-enrichment.md) |
| Find people at your target accounts | [Account prospecting](https://docs.waterfall.io/v1/use-cases/account-prospecting.md) |
| Fill gaps in contact and company records | [CRM enrichment](https://docs.waterfall.io/v1/use-cases/crm-enrichment.md) |
| Check where existing contacts work | [Job changes](https://docs.waterfall.io/v1/use-cases/job-changes.md) |
| Check an email before outreach | [Email verification](https://docs.waterfall.io/v1/use-cases/email-verification.md) |
| Identify companies visiting your website | [Website company identification](https://docs.waterfall.io/v1/use-cases/website-company-identification.md) |

## How the API works

Send requests to `https://api.waterfall.io` with your API key in the `x-api-key` header. [Authentication](https://docs.waterfall.io/v1/authentication.md) covers access and key management.

Prospector and the contact, phone, and company enrichment APIs return a `job_id`. Use the matching Finder to retrieve the result, or provide a `webhook_url` to receive it. Search and verification APIs return results in the same request. The [API selection guide](https://docs.waterfall.io/v1/introduction.md) lists the response pattern and availability for each capability.

Every reference page shows the supported inputs and outputs. Use [Usage Tracking](https://docs.waterfall.io/v1/inline-usage.md) to read returned costs, and [Account Reporting](https://docs.waterfall.io/v1/account-reporter-v2.md) for usage across a date range.

For API access, pricing, or help choosing the right workflow, [talk to the Waterfall team](mailto:support@waterfall.io). Common product and integration questions are covered in the [FAQ](https://docs.waterfall.io/v1/faq.md).


This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.